Gunman opens fire on concert-goers on the popular Las Vegas Strip in the deadliest US mass shooting in modern history.

At least 59 people have been killed and more than 527 injured after at least one gunman opened fire on concert-goers on the popular Las Vegas Strip in the US state of Nevada, AL JAZEERA reported.

Law enforcement authorities have discovered an arsenal of weapons and ammunition from the hotel room and house of the gunman.

A total of 42 guns were found in the hotel room and house of 64-year-old Stephen Paddock, who rained down a barrage of bullets from the 32nd floor of the Mandalay Bay Hotel towards an open-air concert Sunday night, police said.

The mass shooting took place late on Sunday outside a building at the Mandalay Bay Resort and Casino during the Route 91 country festival. More than 22,000 people were in attendance at the concert.

Police named the shooter as 64-year-old Stephen Paddock, who they said fired into the crowd from the 32nd floor of the Mandalay Bay hotel.

“He was later found dead in his hotel room,” a police statement said.

Eric Paddock, Stephen's brother, said on CNN that his brother had ‘absolutely’ had no mental problems or political motives that the family was aware of.

Cole Watson, who was at the concert with his wife and kids, said, “At first it sounded like someone was setting off a whole lot of fire crackers.